Not like I'm a expert but we did long term test drive on those two..
The GX is basically a more "Presentable" Land cruiser , shorter and taller but as far as I know is the same drivetrain and suspension, I do love the sideways opening rear door..
the Sequoia is much closer to a Escalade, suburban, never took it to moab but just studying the way is build is a step don't on "quality and purpose"
we end up with a Lc100, purchase with 210.000 miles no is almost 350.000 zero issues beside replacing some of the front end parts (worn out) and Ooh they are silly expensive but the quality is top notch..
Actually the one you need is this one, but look selling your children to afford one.. (only one in the US at the salt lake city museum (A guy working there is the one that lend us the three toyotas to drive)